


twisting nerve like wire

by EnRaa



Category: Undertale (Video Game)
Genre: Choking, Ecto-Genitalia (Undertale), Enthusiastic Consent, Explicit Sexual Content, Kink Discovery, Light Bondage, M/M, Masochism, Masturbation, Under-negotiated Kink, Underfell Sans (Undertale), kustard - Freeform
Language: English
Status: Completed
Published: 2021-02-16
Updated: 2021-02-16
Packaged: 2021-03-17 13:47:20
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,765
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29472687
Author URL: https://archiveofourown.org/users/EnRaa/pseuds/EnRaa
Summary: Red knows personally how dangerous he is with proper ammunition, and briefly, he wonders if he should worry that Sans is the same. The look that flashes over Sans' face, like he's got a new trinket beneath his hands to take apart, tells Red he's exactly the same.
Relationships: Sans/Sans (Undertale)
Kudos: 28





	twisting nerve like wire

It's weird feeling, being pinned beneath Sans. Being pinned in general, really; Red isn't keen on putting himself in these positions, likes to maintain a certain level of control when it came to these sorts of things.

He finds himself oddly pliant where Sans is concerned, and Red considers that he lets it slide knowing he can easily dislodge the slightly smaller version of himself. He can overpower him bound and blindfolded, if need be, and Sans' white, fragile bones, not weathered or battle hardened, would splinter beneath his touches _so easily_ if he so intended.

But his intent had apparently deserted him and left a nice, sturdy hole for curiosity to creep into instead, and so Red stares up at his (somewhat) nicer double, flashing him a crooked grin that Sans awards as his phalanges drift over Red's broader rib cage, the distals of his thumbs coming to trace his sternum so purposefully, kneading the dense bone like a masseuse kneads a muscle.

The touch, confident and practiced, draws a shuddery sigh from Red, a suden sound like it was kicked out of him, and Sans smiles down at him, all sickeningly sweet and smug as hell.

Red tries once more to move his arms, still pinned beneath Sans's legs, and finds not an ounce of give.

He could force it.

He doesn't.

Sans cocks his skull when he feels the tension in Red's arms beneath him, and Red hates how sincere his stupid voice is when he asks, “you okay?”, like pinning him down wasn't discussed in the first place. He keeps rubbing over his sternum, though with less force now, like he's trying to be comforting. He hates how loving it is, has to brush it off, so Red just chuckles at him. Really, it's cute that Sans thinks restraint will make him back out? Adorable, even, that he thinks he wouldn't be tossed off like a ragdoll if Red really didn't like this.

“'m fine,” Red grunts, and just to make Sans think before he needlessly worries next time (and to be the asshole they both know he is), he bucks his pelvis sharply, watching gleefully as Sans scrabbles for balance. Sans catches himself pretty easily, reaching out with both hands and wrapping them instinctively around anything for support, and that anything just happened to be Red's cervical spine.

And damn if he didn't gasp at that. Sadly, neither of them are innocent enough to believe it was a pained gasp, either. They both know exactly what kind of reaction that was, and Red can only look at Sans.

Sans' eyelights flash for a moment as he takes in Red's reaction, stares down at his hands, wrapped around Red's neck like a noose, then looks back up at Red. Red meets his eyelights, daring Sans to say something about it.

Yes, he likes being choked. Big deal. 

"huh..." Sans says slowly as he watches Red, and Red knows his own expression, the way he eyes Sans warily, is giving away just how much he regretted that reaction, how much he regretted handing Sans ammunition.

Red knows personally how dangerous he is with proper ammunition, and briefly, he wonders if he should worry that Sans is the same. The look that flashes over Sans' face, like he's got a new trinket beneath his hands to take apart, tells Red he's exactly the same, and Red wants desperately to sink into the bed and go back, just a few moments, to before Sans found the upper hand.

Sans leans forward, just a bit, and the tightness, the sudden weight, makes his magic flare disgustingly and begin to pool in his pelvis. While he had enough mind to school his expression, nothing can cover up how his magic screams out how into this he is. Sans _knows_ , too, flashes Red a gleeful grin as leans his weight down even more, using Red's spine for support as he adjusts his position over Red.

He tries desperately not to react, he really does. Beneath Sans' legs, he balls his hands into fists, digs his distals into his carpals. Anything to block out, hell, even _numb_ , the pressure on his spine, because like hell is he letting Sans know how easily it winds him up.

Too easily, really. It's almost embarrassing.

The weight lifts off, suddenly, and Red let's out a breath he didn't know he'd been holding. He can feel the residual ache in the bone, dull and ever-present like a too-tight collar. Sans stares down at him, eyelights a little hazy, and Red can smell how wet Sans is, can feel the wet heat where he straddles him, even through Sans' shorts. It makes him wish his hands were free to investigate a little farther, to feel for himself how aroused Sans is.

“enjoyin' yerself, sweetheart?” Red asks in a voice that's too scratchy, even for him. It's more a croak as his bones resettle, but it apparently is right up Sans' alley, if the throb of heat from his magic is anything to go by.

“you sound _wrecked_...” Sans marvels, and he rubs gentle circles into Red's spine, like he's soothing the bone. Red can't help how he tilts his skull back, giving Sans all the access he could ever want, and Sans takes advantage, pressing a thumb distal in _hard_ here and there just to feel Red shudder. Well, if they're both going down, he can lose a little dignity and at least enjoy himself. 

“s'all yer doin'...” Red growls, though there's no bite to it, and Sans huffs a laugh.

“yeah. guess so.” He agrees and leans back onto Red, taking one of his hands off of Red's spine. He licks the distals, never breaking eye contact with Red, and slips his hand into his shorts.

His nicer, milder self really knew how to be a real fucking tease.

“why don't ya shimmy on up here...?” Red suggests hoarsely, and he flexes his arms under Sans' legs with a little more effort, just in case Sans got careless. Which he didn't. Sans doesn't budge, and even leans harder onto his legs for good measure. Red sees more things in common between them every damn day. His eyelights fall on to Sans' hand, the outline so obvious through the thin fabric, and watches the gentle rotations of his carpals like he's hypnotized. Sans arches his hips up into his hand with a sigh, putting on quite a pretty show, and Red's mouth waters. “my mouth'll feel a whole lot better than yer fingers...” He promises, and Sans chuckles airily.

“mm, i got it _hand_ led, thanks...” He says with a grin, and Red shifts uncomfortably as his magic throbs in his pelvis, begging to take shape. The thumb still circling his spine is doing nothing to help that, each touch prickling as it presses just right on what will surely be a beautiful set of bruises later.

He hopes they'll be good bruises, anyway. It feels promising.

“ya sure? i hear i got a wicked tongue...” He catches sight of Sans' hand stopping, then dipping _in_ , and Red groans at the same time Sans let's out a pleased sigh as he sinks down onto his own phalanges. He opens his mouth, another teasing offer ready, but Sans leans forwards again, pressing down hard on Red's spine. His words die on his tongue as he watches through hazy eyelights as Sans' hips stutter onto his hand.

"least i found one way to shut you up," Sans says, his tone light and teasing, and Red can feel the way Sans' weight shifts where his legs pin him down, the way it rocks through his femurs, and he can't help the wheezing moan that erupts as he takes it all in. "well, sort of..." He adds, and his eyelights flare as he gives a shuddery moan. The hand around Red's neck tightens briefly, and he hears the wet sounds of Sans' fingers as he rides them. It drives him wild, and his magic snaps into place, though he doubts Sans will have enough pity to stop teasing and ride _him_.

"Red..." Sans sighs as he tips his skull back, his hand tightening just that extra little bit, and Red feels the full body shudder Sans gives as he comes. Feels how his hips buck into his hand, no real rhythm anymore, just raw pleasure seeking. Red watches with rapt attention as his hand slows to a stop as he comes down, and the hand wrapped around Red's spine loosens even slower. Eventually he pulls it off altogether, and Red feels that ache settle in once more.

He'll definitely have some good bruises. It'll make for wicked revenge, flaunting them tomorrow and teasing Sans endlessly about it.

"fuck, sweetheart..." He croaks, and Sans shuffles back, lifting his legs off of Red's forearms. Red lifts his arms, feeling an ache there, as well, and settles his hands on Sans' iliac crests. He's achy, but not enough to be useless. "ya really got into that." 

Sans chuckles awkwardly. "you're okay, right? i didn't go too far?" He trails his hands along Red's arms, rubbing up over the radius, then down the ulna, and finally coming to rest over Red's own hands.

Red gives him an awful smug grin for a guy who didn't get off yet. "never been better," He says with as easy a tone as he can manage when his voice sounds like gravel. "love watchin' you like that..." He massages the edges of Sans' crests with his thumbs, and doesn't miss how Sans' hip tip up into his touch.

"i liked watching _you_..." Sans admits, and his voice is quiet, like he's ashamed of it even after just getting off on it in Red's lap, an Red is having none of that.

"ya like having me under yer thumb, kitten?" He presses, loving the hue of blue magic that spreads over Sans' face. "wanna take me apart, piece by piece?"

"mm, maybe..." His hips spread a little wider, and Red can feel Sans' magic pooling in his pelvis again, can feel the heat licking at his hands, and he gives him a wolfish grin.

"then why don't ya c'mon up here and see what else makes me tick, then?" It's not an invitation he'd give to most, too wary to let anyone in on a good day, but Sans was, as usual, the outlier. And with the way Sans grins and climbs up so he's straddling his ribs, he thinks he definitely made the right decision.

**Author's Note:**

> Funny enough, this was somewhat inspired from work where a coworker put me in a trach chokehold. It was a very funny moment of, "I'm fine, this is fine, huh, now my trachea is closed over, weird..." ¯\\_(ツ)_/¯


End file.
